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llvm-dwarfdump: Lookup type units when prettyprinting types
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This handles DWARFv4 and DWARFv5 type units, but not Split DWARF type
units. That'll come in a follow-up patch.
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@dwblaikie
dwblaikie committed Nov 10, 2021
1 parent f30a8a6 commit 58b1b64
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Showing 6 changed files with 479 additions and 31 deletions.
6 changes: 5 additions & 1 deletion cross-project-tests/debuginfo-tests/clang_llvm_roundtrip/simplified_template_names.cpp
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Original file line number Diff line number Diff line change
@@ -1,4 +1,8 @@
// RUN: %clang %target_itanium_abi_host_triple %s -c -o - -g -Xclang -gsimple-template-names=mangled -Xclang -debug-forward-template-params -std=c++20 \
// RUN: %clang %target_itanium_abi_host_triple %s -c -o - -gdwarf-4 -Xclang -gsimple-template-names=mangled -Xclang -debug-forward-template-params -std=c++20 \
// RUN: | llvm-dwarfdump --verify -
// RUN: %clang %target_itanium_abi_host_triple %s -c -o - -gdwarf-4 -Xclang -gsimple-template-names=mangled -Xclang -debug-forward-template-params -std=c++20 -fdebug-types-section \
// RUN: | llvm-dwarfdump --verify -
// RUN: %clang %target_itanium_abi_host_triple %s -c -o - -gdwarf-5 -Xclang -gsimple-template-names=mangled -Xclang -debug-forward-template-params -std=c++20 -fdebug-types-section \
// RUN: | llvm-dwarfdump --verify -
#include <cstdint>
template<typename ...Ts>
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1 change: 1 addition & 0 deletions llvm/include/llvm/DebugInfo/DWARF/DWARFContext.h
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Expand Up @@ -243,6 +243,7 @@ class DWARFContext : public DIContext {
}

DWARFCompileUnit *getDWOCompileUnitForHash(uint64_t Hash);
DWARFTypeUnit *getTypeUnitForHash(uint16_t Version, uint64_t Hash);

/// Return the compile unit that includes an offset (relative to .debug_info).
DWARFCompileUnit *getCompileUnitForOffset(uint64_t Offset);
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2 changes: 2 additions & 0 deletions llvm/include/llvm/DebugInfo/DWARF/DWARFDie.h
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Expand Up @@ -182,6 +182,8 @@ class DWARFDie {
DWARFDie getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const;
DWARFDie getAttributeValueAsReferencedDie(const DWARFFormValue &V) const;

DWARFDie resolveTypeUnitReference() const;

/// Extract the range base attribute from this DIE as absolute section offset.
///
/// This is a utility function that checks for either the DW_AT_rnglists_base
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21 changes: 21 additions & 0 deletions llvm/lib/DebugInfo/DWARF/DWARFContext.cpp
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Expand Up @@ -693,6 +693,27 @@ void DWARFContext::dump(
getDebugNames().dump(OS);
}

DWARFTypeUnit *DWARFContext::getTypeUnitForHash(uint16_t Version,
uint64_t Hash) {
// FIXME: Include support for Split DWARF here
parseNormalUnits();

auto IsTypeWithHash = [&](const std::unique_ptr<DWARFUnit> &Unit) {
DWARFTypeUnit *TU = dyn_cast<DWARFTypeUnit>(Unit.get());
if (!TU)
return false;
return TU->getTypeHash() == Hash;
};
auto I = llvm::find_if(types_section_units(), IsTypeWithHash);
if (I != types_section_units().end())
return cast<DWARFTypeUnit>(I->get());
// Search normal .debug_info units in case it's a DWARFv5 type unit.
I = llvm::find_if(normal_units(), IsTypeWithHash);
if (I != types_section_units().end())
return cast<DWARFTypeUnit>(I->get());
return nullptr;
}

DWARFCompileUnit *DWARFContext::getDWOCompileUnitForHash(uint64_t Hash) {
parseDWOUnits(LazyParse);

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77 changes: 47 additions & 30 deletions llvm/lib/DebugInfo/DWARF/DWARFDie.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -108,6 +108,14 @@ static void dumpLocationExpr(raw_ostream &OS, const DWARFFormValue &FormValue,
return;
}

static DWARFDie resolveReferencedType(DWARFDie D,
dwarf::Attribute Attr = DW_AT_type) {
return D.getAttributeValueAsReferencedDie(Attr).resolveTypeUnitReference();
}
static DWARFDie resolveReferencedType(DWARFDie D, DWARFFormValue F) {
return D.getAttributeValueAsReferencedDie(F).resolveTypeUnitReference();
}

namespace {

// FIXME: We should have pretty printers per language. Currently we print
Expand Down Expand Up @@ -181,7 +189,7 @@ struct DWARFTypePrinter {
DWARFDie skipQualifiers(DWARFDie D) {
while (D && (D.getTag() == DW_TAG_const_type ||
D.getTag() == DW_TAG_volatile_type))
D = D.getAttributeValueAsReferencedDie(DW_AT_type);
D = resolveReferencedType(D);
return D;
}

Expand Down Expand Up @@ -209,7 +217,7 @@ struct DWARFTypePrinter {
OS << "void";
return DWARFDie();
}
DWARFDie Inner = D.getAttributeValueAsReferencedDie(DW_AT_type);
DWARFDie Inner = resolveReferencedType(D);
const dwarf::Tag T = D.getTag();
switch (T) {
case DW_TAG_pointer_type: {
Expand Down Expand Up @@ -240,8 +248,7 @@ struct DWARFTypePrinter {
OS << '(';
else if (Word)
OS << ' ';
if (DWARFDie Cont =
D.getAttributeValueAsReferencedDie(DW_AT_containing_type)) {
if (DWARFDie Cont = resolveReferencedType(D, DW_AT_containing_type)) {
appendQualifiedName(Cont);
OS << "::";
}
Expand Down Expand Up @@ -339,10 +346,9 @@ struct DWARFTypePrinter {
case DW_TAG_pointer_type: {
if (needsParens(Inner))
OS << ')';
appendUnqualifiedNameAfter(
Inner, Inner.getAttributeValueAsReferencedDie(DW_AT_type),
/*SkipFirstParamIfArtificial=*/D.getTag() ==
DW_TAG_ptr_to_member_type);
appendUnqualifiedNameAfter(Inner, resolveReferencedType(Inner),
/*SkipFirstParamIfArtificial=*/D.getTag() ==
DW_TAG_ptr_to_member_type);
break;
}
/*
Expand Down Expand Up @@ -387,7 +393,7 @@ struct DWARFTypePrinter {
appendTemplateParameters(C, FirstParameter);
}
if (C.getTag() == dwarf::DW_TAG_template_value_parameter) {
DWARFDie T = C.getAttributeValueAsReferencedDie(DW_AT_type);
DWARFDie T = resolveReferencedType(C);
Sep();
if (T.getTag() == DW_TAG_enumeration_type) {
auto V = C.find(DW_AT_const_value);
Expand Down Expand Up @@ -523,9 +529,8 @@ struct DWARFTypePrinter {
continue;
auto TypeAttr = C.find(DW_AT_type);
Sep();
appendQualifiedName(TypeAttr
? C.getAttributeValueAsReferencedDie(*TypeAttr)
: DWARFDie());
appendQualifiedName(TypeAttr ? resolveReferencedType(C, *TypeAttr)
: DWARFDie());
}
if (IsTemplate && *FirstParameter && FirstParameter == &FirstParameterValue)
OS << '<';
Expand All @@ -534,15 +539,15 @@ struct DWARFTypePrinter {
void decomposeConstVolatile(DWARFDie &N, DWARFDie &T, DWARFDie &C,
DWARFDie &V) {
(N.getTag() == DW_TAG_const_type ? C : V) = N;
T = N.getAttributeValueAsReferencedDie(DW_AT_type);
T = resolveReferencedType(N);
if (T) {
auto Tag = T.getTag();
if (Tag == DW_TAG_const_type) {
C = T;
T = T.getAttributeValueAsReferencedDie(DW_AT_type);
T = resolveReferencedType(T);
} else if (Tag == DW_TAG_volatile_type) {
V = T;
T = T.getAttributeValueAsReferencedDie(DW_AT_type);
T = resolveReferencedType(T);
}
}
}
Expand All @@ -552,12 +557,10 @@ struct DWARFTypePrinter {
DWARFDie T;
decomposeConstVolatile(N, T, C, V);
if (T && T.getTag() == DW_TAG_subroutine_type)
appendSubroutineNameAfter(T,
T.getAttributeValueAsReferencedDie(DW_AT_type),
false, C.isValid(), V.isValid());
appendSubroutineNameAfter(T, resolveReferencedType(T), false, C.isValid(),
V.isValid());
else
appendUnqualifiedNameAfter(
T, T.getAttributeValueAsReferencedDie(DW_AT_type));
appendUnqualifiedNameAfter(T, resolveReferencedType(T));
}
void appendConstVolatileQualifierBefore(DWARFDie N) {
DWARFDie C;
Expand All @@ -567,7 +570,7 @@ struct DWARFTypePrinter {
bool Subroutine = T && T.getTag() == DW_TAG_subroutine_type;
DWARFDie A = T;
while (A && A.getTag() == DW_TAG_array_type)
A = A.getAttributeValueAsReferencedDie(DW_AT_type);
A = resolveReferencedType(A);
bool Leading =
(!A || (A.getTag() != DW_TAG_pointer_type &&
A.getTag() != llvm::dwarf::DW_TAG_ptr_to_member_type)) &&
Expand Down Expand Up @@ -611,7 +614,7 @@ struct DWARFTypePrinter {
for (DWARFDie P : D) {
if (P.getTag() != DW_TAG_formal_parameter)
return;
DWARFDie T = P.getAttributeValueAsReferencedDie(DW_AT_type);
DWARFDie T = resolveReferencedType(P);
if (SkipFirstParamIfArtificial && RealFirst && P.find(DW_AT_artificial)) {
FirstParamIfArtificial = T;
RealFirst = false;
Expand All @@ -631,7 +634,7 @@ struct DWARFTypePrinter {
DWARFDie C;
DWARFDie V;
auto CVStep = [&](DWARFDie CV) {
if (DWARFDie U = CV.getAttributeValueAsReferencedDie(DW_AT_type)) {
if (DWARFDie U = resolveReferencedType(CV)) {
if (U.getTag() == DW_TAG_const_type)
return C = U;
if (U.getTag() == DW_TAG_volatile_type)
Expand All @@ -658,8 +661,7 @@ struct DWARFTypePrinter {
OS << " &";
if (D.find(DW_AT_rvalue_reference))
OS << " &&";
appendUnqualifiedNameAfter(
Inner, Inner.getAttributeValueAsReferencedDie(DW_AT_type));
appendUnqualifiedNameAfter(Inner, resolveReferencedType(Inner));
}
void appendScopes(DWARFDie D) {
if (D.getTag() == DW_TAG_compile_unit)
Expand All @@ -670,6 +672,7 @@ struct DWARFTypePrinter {
return;
if (D.getTag() == DW_TAG_subprogram)
return;
D = D.resolveTypeUnitReference();
if (DWARFDie P = D.getParent())
appendScopes(P);
appendUnqualifiedName(D);
Expand Down Expand Up @@ -761,7 +764,7 @@ static void dumpAttribute(raw_ostream &OS, const DWARFDie &Die,
DINameKind::LinkageName))
OS << Space << "\"" << Name << '\"';
} else if (Attr == DW_AT_type) {
DWARFDie D = Die.getAttributeValueAsReferencedDie(FormValue);
DWARFDie D = resolveReferencedType(Die, FormValue);
if (D && !D.isNULL()) {
OS << Space << "\"";
DWARFTypePrinter(OS).appendQualifiedName(D);
Expand Down Expand Up @@ -873,13 +876,27 @@ DWARFDie::getAttributeValueAsReferencedDie(dwarf::Attribute Attr) const {

DWARFDie
DWARFDie::getAttributeValueAsReferencedDie(const DWARFFormValue &V) const {
DWARFDie Result;
if (auto SpecRef = V.getAsRelativeReference()) {
if (SpecRef->Unit)
return SpecRef->Unit->getDIEForOffset(SpecRef->Unit->getOffset() + SpecRef->Offset);
if (auto SpecUnit = U->getUnitVector().getUnitForOffset(SpecRef->Offset))
return SpecUnit->getDIEForOffset(SpecRef->Offset);
Result = SpecRef->Unit->getDIEForOffset(SpecRef->Unit->getOffset() +
SpecRef->Offset);
else if (auto SpecUnit =
U->getUnitVector().getUnitForOffset(SpecRef->Offset))
Result = SpecUnit->getDIEForOffset(SpecRef->Offset);
}
return DWARFDie();
return Result;
}

DWARFDie DWARFDie::resolveTypeUnitReference() const {
if (auto Attr = find(DW_AT_signature)) {
if (Optional<uint64_t> Sig = Attr->getAsReferenceUVal()) {
if (DWARFTypeUnit *TU =
U->getContext().getTypeUnitForHash(U->getVersion(), *Sig))
return TU->getDIEForOffset(TU->getTypeOffset() + TU->getOffset());
}
}
return *this;
}

Optional<uint64_t> DWARFDie::getRangesBaseAttribute() const {
Expand Down
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